They utilized a variety of biochemical tracing techniques - including stable isotope analysis, fatty acid analysis, and environmental DNA - to help better understand the feeding habits and habitats of the species. There’s not very many animals that do something quite like this.” Collaborative researchįor this study, the researchers used 14 Cookiecutter sharks that were collected by the Monterey Bay Aquarium from the Central Pacific around Hawaii. “They feed on everything from the biggest, toughest apex predators - like white sharks, orcas, everything you can imagine - down to the smallest little critters. “These animals occupy a unique ecological role in the world’s oceans,” said Carlisle. “It turns out that all these bites we see on marine mammals and larger sport and commercial fishes and things really make up a relatively smaller amount of their diet.”Ĭarlisle noted that it is unique to have an animal that will feed on creatures from the top and the bottom of the food chain. So our question was, ‘Are we biased by what we’re seeing?’ ” said Carlisle. “At the end of the day, the paradigm was that the sharks would primarily feed on these larger animals, but we just didn’t have any empirical data. When researchers did study the sharks, they could only look at what was physically in the sharks’ stomachs - which sometimes, was nothing at all - and make inferences from the bites they had seen on their larger species, but they could not employ the more advanced scientific methods now available to researchers. The feeding habits of Cookiecutters have been little studied - Carlisle said there have been maybe 150 Cookiecutter stomachs studied around the world over the last 50 years. While these sharks are widely distributed throughout the world, and may be one of the more common sharks in the ocean, because they live in the deep sea, and are never held in captivity there is little known about them - especially when it comes to their eating habits.Ī new study led by the University of Delaware’s Aaron Carlisle has uncovered the potential diet and habitat of these Cookiecutter sharks, showing that while they might chomp on everything they can get their jaws on in the upper reaches of the ocean to supplement their diets, they primarily feed on the little critters they share a habitat with such as crustaceans, squid and small fish.Ĭarlisle, assistant professor in the School of Marine Science and Policy in UD’s College of Earth, Ocean and Environment, said that for years, researchers assumed that Cookiecutter sharks were coming up at night, feeding on whales and bigger animals, and then heading back to the deep ocean and hanging out during the day.
These bites were not only restricted to animals, as submarines in the 1970s and 1980s were having their rubber coated sonar sensors bitten in this same fashion and underwater electrical cables were also found to have the odd-shaped bites.Įventually, it was discovered that the culprit was a small shark that is distributed throughout the world’s tropical and subtropical oceanic waters named the Cookiecutter shark (Isistius brasiliensis).
Those fresh bites and scars were almost like someone took a cookie cutter and surgically removed a hunk of tissue. Newswise - For years, researchers studying marine life in the wild would occasionally come across animals - such as dolphins, swordfish, leatherback sea turtles, whales, white sharks and even humans -with oddly shaped plugs of tissue taken out of their bodies.
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